在 Rust 中使用 Tokio-postgres 向 Postgres 插入多个值
multiple value inserts to Postgres using Tokio-postgres in Rust
我正在使用以下代码通过 tokio-postgres 插入到 Postgres 数据库中,有没有更好的选择:
let members = &[obj] //obj is a struct
let mut params = Vec::<&(dyn ToSql + Sync)>::new();
let mut i = 1;
let mut qry:String = "insert into tablename(id,userid,usertype) values".to_string();
for column in members{
if(i ==1){
qry = format!("{} (${},${},${})",qry,i,i+1,i+2);
}else{
qry = format!("{}, (${},${},${})",qry,i,i+1,i+2);
}
params.push(&column.id);
params.push(&column.userid);
params.push(&column.usertype);
i = i+3;
}
println!("qry : {}",qry);
let result = p.execute(&qry, ¶ms[..]).await; //p is the pool manager
否:
- Inserting multiple values at the same time
- Ability to insert multiple rows by specifying multiple rows in VALUES?
您可以通过使用迭代器略微改进它:
use itertools::Itertools; // For tuples() and format_with()
let params: Vec<_> = members
.iter()
.flat_map(|row| [&row.id as &(dyn ToSql + Sync), &row.userid, &row.usertype])
.collect();
let query = format!(
"insert into tablename(id, userid, usertype) values {}",
(0..params.len())
.tuples()
.format_with(", ", |(i, j, k), f| {
f(&format_args!("(${i}, ${j}, ${k})"))
}),
);
不过我真的不认为那更好。
我正在使用以下代码通过 tokio-postgres 插入到 Postgres 数据库中,有没有更好的选择:
let members = &[obj] //obj is a struct
let mut params = Vec::<&(dyn ToSql + Sync)>::new();
let mut i = 1;
let mut qry:String = "insert into tablename(id,userid,usertype) values".to_string();
for column in members{
if(i ==1){
qry = format!("{} (${},${},${})",qry,i,i+1,i+2);
}else{
qry = format!("{}, (${},${},${})",qry,i,i+1,i+2);
}
params.push(&column.id);
params.push(&column.userid);
params.push(&column.usertype);
i = i+3;
}
println!("qry : {}",qry);
let result = p.execute(&qry, ¶ms[..]).await; //p is the pool manager
否:
- Inserting multiple values at the same time
- Ability to insert multiple rows by specifying multiple rows in VALUES?
您可以通过使用迭代器略微改进它:
use itertools::Itertools; // For tuples() and format_with()
let params: Vec<_> = members
.iter()
.flat_map(|row| [&row.id as &(dyn ToSql + Sync), &row.userid, &row.usertype])
.collect();
let query = format!(
"insert into tablename(id, userid, usertype) values {}",
(0..params.len())
.tuples()
.format_with(", ", |(i, j, k), f| {
f(&format_args!("(${i}, ${j}, ${k})"))
}),
);
不过我真的不认为那更好。